How to Pause Program Execution in C using Sleep Functions?

Seeking a Sleep Function in C

In pursuit of controlling program execution flow, you may encounter the need to pause the program for a specified duration. In C , there's no direct equivalent to the commonly used Sleep(time) function found in other languages. However, the C standard library provides a viable alternative.

Introducing std::this_thread::sleep_for

The C Standard Library offers the std::this_thread::sleep_for function, which allows you to suspend the current thread's execution for a specified duration. To use it, you'll need to include the following headers:

<code class="cpp">#include <chrono>
#include <thread></code>

The syntax of std::this_thread::sleep_for is as follows:

<code class="cpp">void sleep_for(const std::chrono::duration& timespan);</code>

Where timespan is a std::chrono::duration object specifying the duration of the sleep. To create a millisecond-based std::chrono::duration, use the std::chrono::milliseconds constructor:

<code class="cpp">std::chrono::milliseconds timespan(111605);</code>

Using these components, you can halt the execution of your program for the desired time interval:

<code class="cpp">std::this_thread::sleep_for(timespan);</code>

Note that std::this_thread::sleep_until serves as a complementary function for precise time-based synchronization.

Legacy Sleep Options (Pre-C 11)

Prior to the introduction of C 11, the language lacked thread functionality and sleep capabilities. Consequently, the solution to suspend execution was platform-dependent. For Windows or Unix, you might have relied on something like this:

<code class="cpp">#ifdef _WIN32
    #include <windows.h>
    
    void sleep(unsigned milliseconds)
    {
        Sleep(milliseconds);
    }
#else
    #include <unistd.h>
    
    void sleep(unsigned milliseconds)
    {
        usleep(milliseconds * 1000); // takes microseconds
    }
#endif</code>

Alternatively, you could have simplified the implementation using the Boost library's boost::this_thread::sleep.

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